Thirds to samuel reese pritchard and john curtis schooley



(No Model.)

N. J. PRITOHARD. VARIABLE SPEED HEARING.

No. 515,534. Patented Feb. 27, 1894 ms mmumu. unmuu-ma ooMPANv.

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UNITED STATES PATENT NATHANIEL J. PRITGHARD, OF SHENANDOAH, VIRGINIA,ASSIGNOR OF TWO- THIBDS TO SAMUEL REESE PRITCHAR-D AND JOHN CURTISSCHOOLEY,

OF SAME PLACE.

VARIABLE-SPEED GEARING.

SPECIFICATION forming part of Letters Patent No. 515,534, dated February27,

Application filed April 29, 1898.

Serial No. 472,331. (No model.)

To aZZ whom, it may concern.-

Be it known that I, NATHANIEL J. PRITCH- ARD, a citizen of the UnitedStates, residing at Shenandoah, in the county of Page and State 5 ofVirginia, have invented certainnew and useful Improvements inVariable-Speed Gearing; and I do hereby declare the following to beafull, clear, and exact description of the invention, such as willenable others skilled in the art to which it appertains to make and usethe same.

This invention relates to a speed mechanism for bicycles, velocipedes orother similar machinery.

The object is to provide means for easily increasing the speed a greateror less extent whenever desired, said means being entirely under thecontrol of the rider at all times.

The present invention is an improvement upon that shown and described inmy other pending application for Letters-Patent, filed October 24, 1892,Serial No. 449,874, and it consists essentially in the construction,arrangement and combination of parts, substantially as will behereinafter described and claimed.

In the annexed drawings illustrating my invention: Figure 1 is aperspective view of a portion of a bicycle provided with my presentimprovements. Fig. 2 is an enlarged vertical 3o sectional elevation ofmy improved speed increasing mechanism showing the same applied to apedal shaft of a safety bicycle. Fig. 3 is a right hand end elevation ofthe sprocket wheel and the mechanical parts ar- 3 5 ranged within thesame.

Similar letters of reference designate corresponding parts throughoutthe several figures of the drawings.

My speed increasing mechanism is applicable to many difierent kinds ofmachinery. It

is particularly useful in connection with bicycles or other velocipedes.In the present case I shall explain the same as applied to a pedal shaftof a safety bicycle. It is not to be inferred however that I considermyself restricted to this use of the invention, but I explicitly statethat it may be used in any connection where it is found serviceable andadvantageous.

A denotes the pedal shaft of abioyc1e,pro-

vided with the pedal cranks a. a adapted to v carry the pedals at theirouter ends.

C denotes the sprocket or chain wheel. It is made in the peculiar shapeshown in Fig. 2, having an outer toothed rim which is connectedto asleeve-like or annular rim 0 of considerably less diameter than theouter cogged rim, by means preferably of the inclined or conical shapedconnection 0. This form of the sprocket wheel construction may howevervary. 1 simply employ it for the purpose of properly locating the coggedrim from the adjacent pedal shaft and yet place the multiplying gearingat the desired point upon the pedal shaft. The conical part chowever ofthe sprocket Wheel maybe more or less inclined or straight if preferred.The rim 0' has an internal series of cogs or teeth to provide a gearwheel 0 all as clearly shown in, Fig. 2.

On the shaft A near the left hand pedal shaft a is a disk D, rigidlysecured thereto and having a peripheral flange (1 whereby the peripheryof the disk D is enabled to have a peripheral shoulderor rabbet thereonto contain a series of balls (7 which constitutes a ball bearing, saidballs being located as shown in Fig. 2, neatly between the flange 01 anda corresponding horizontal flange on theframe C of the sprocket wheel.The disk D is therefore practically located inside of the sprocket wheelrim 0. This disk D carries a pinion E, supported by a stud or journal.held horizontally in the disk D. The pinion E engages the teeth of thegear wheel 0 The pinion E likewise engages the teeth of a small gearwheel F which loosely surrounds shaft A, being integral with asleeve Fwhich is screwed into the wheel G and thereby rigidly connected to saidwheel G. Thus it will be seen that the three gears 0 E and F lie in thesame vertical plane or in other words are situated in line with eachother, being in engagement as shown clearlyin Figs. 2 and 3.

The wheel G is formed integral with a grooved rim 1, adapted for theapplication thereto of a brake strap or brakeshoe, which by pressingthereon can retard the motion of the wheelG or stop it entirely. Thewheel G obviously is loose upon shaft A. Wheel Gis too formed near itsperiphery with a flange and rabbet to containthe balls constituting acircular series and providing a ball bearing, which balls are locatedbetween the periphery of Wheel G and a corresponding flange c on the rimC of the sprocket wheel. Thus it will be seen that on one side of thevertical train of gears C E and F is located the fixed disk D,withaball-bearingbetweenit and the sprocket wheel, while on the otherside ofsaid train of gears is the loose friction wheel with a ballbearing between it and the sprocket wheel, both fixed pulley and thefriction wheel being practically situated inside of the sprocket wheel.

In Fig. 3, I have shown a couple of pawls II II pivoted to the innerface of the disk D and having springs h h bearing upon them to forcetheir teeth into engagementwith the teeth of the internally cogged gear0 This arrangement of pawls is for the purpose of preventing anybackward movement of the sprocket wheel and causing the result of themovement of the intermeshed gears'to be forward or in a proper directionof rotation to propel the bicycle in the right manner.

Suitable connections may be made between the frictionally acting wheeland the brake shoe or strap which is applied thereto and a leversituated near the steering head of the machine so that the rider may atany time apply the brake strap to or release it from the friction rim I,thereby stopping, retarding or permitting the latter to start. It willbe evident that as the shaft A revolves, disk D will likewise revolve,carrying with it the pinion E, which will have two motions, one aroundthe axis of the shaft and another on its own axis and since this pinionE is in mesh with the gears C and F, the result will be to drive thesprocket wheel 0 and also the friction wheel I, simultaneously at auniform rate of speed. Such will be the case when the friction wheel isfree to move under the actuation of the gearing. If however we stop thefriction wheel by applying the brake thereto, we make it a fixed wheelor in other Words a dead wheel and this will cause the pinion E to drivethe sprocket O at a much higher rate of speed, say double the speed thatit moved slates heretofore such being the characteristic effect of anepicyclic train of gearing, including one dead or stationary gear. Ifhowever, instead of stopping the friction wheel I G, we simply retard itor slow it up, we will speed up the sprocket Wheel to a certain extentbut not to as high a speed as before. Thus by regulating the action ofthe friction wheel and its speed, we can determine any desired increasefor the speed of the sprocket wheel and conseqnen tly can regulate andeasily govern the speed of the machine.

Having thus described my invention, what Iclaim as new, and desire tosecure by Letters Patent, is

1. In a variable speed mechanism for bicycles, the combination of ashaft, a toothed wheel indirectly supported thereby and having a flangedrim and internally toothed, a disk fast upon the shaft, a ball bearingbetween said disk and the flanged rim, a pinion carried by the disk, asmaller gear on the shaft, said gearing being arranged in a verticalline with the several gears in engagement, and a friction wheelconnected to the smaller gear and having a ball bearing between it andthe flanged rim, and the brake mechanism, all substantially asdescribed.

2. The combination of the shaft, a sprocket wheel having an outertoothed rim and an inner flanged rim, said inner rim being toothed,

a disk fast on the shaft and peripherally flanged so as to permit a ballbearing to be located between it and the flanged rim of the sprocketwheel, a pinion carried by the fixed disk, a smaller gear wheel looseon' th'e shaft, said smaller gear wheel, pinion and internal gear beingin the same vertical plane and in engagement with each other and afriction wheel connected to the smaller loose gear and peripherallyflanged to permit a ball bearing to be located between it and theflanged rim of the sprocket Wheel, together with the brake strap, allsubstantially as described.

In testimony whereof I affix my signature in presence of two witnesses.

NATHANIEL J. PRITOHARD. WVitnesses:

O. J. Scruvnns, (J. L. STEVENS.

